Date: Sat, 9 Jan 2016 22:21:12 +0100 From: Oliver Pinter <oliver.pinter@hardenedbsd.org> To: Konstantin Belousov <kib@freebsd.org> Cc: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r293197 - head/sys/kern Message-ID: <CAPQ4ffvZJKTwX1CSnLgD5v-D0A0feks-uj8G_p7SOAnSeC8grQ@mail.gmail.com> In-Reply-To: <201601051448.u05Eme83057405@repo.freebsd.org> References: <201601051448.u05Eme83057405@repo.freebsd.org>
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On 1/5/16, Konstantin Belousov <kib@freebsd.org> wrote: > Author: kib > Date: Tue Jan 5 14:48:40 2016 > New Revision: 293197 > URL: https://svnweb.freebsd.org/changeset/base/293197 > > Log: > Two fixes for excessive iterations after r292326. > > Advance the logical block number to the lblkno of the found block plus > one, instead of incrementing the block number which was used for > lookup. This change skips sparcely populated buffer ranges, similar > to r292325, instead of doing useless lookups. > > Do not restart the bnoreuselist() from the start of the range if > buffer lock cannot be obtained without sleep. Only retry lookup and > lock for the same queue and same logical block number. > > Reported by: benno > Tested by: pho > Sponsored by: The FreeBSD Foundation > MFC after: 3 days Hi Konstantin! How do you plan to MFC this commit? Only by itself or together with r293059? > > Modified: > head/sys/kern/vfs_default.c > head/sys/kern/vfs_subr.c > > Modified: head/sys/kern/vfs_default.c > ============================================================================== > --- head/sys/kern/vfs_default.c Tue Jan 5 14:21:02 2016 (r293196) > +++ head/sys/kern/vfs_default.c Tue Jan 5 14:48:40 2016 (r293197) > @@ -1080,15 +1080,9 @@ vop_stdadvise(struct vop_advise_args *ap > bsize = vp->v_bufobj.bo_bsize; > startn = ap->a_start / bsize; > endn = ap->a_end / bsize; > - for (;;) { > - error = bnoreuselist(&bo->bo_clean, bo, startn, endn); > - if (error == EAGAIN) > - continue; > + error = bnoreuselist(&bo->bo_clean, bo, startn, endn); > + if (error == 0) > error = bnoreuselist(&bo->bo_dirty, bo, startn, endn); > - if (error == EAGAIN) > - continue; > - break; > - } > BO_RUNLOCK(bo); > VOP_UNLOCK(vp, 0); > break; > > Modified: head/sys/kern/vfs_subr.c > ============================================================================== > --- head/sys/kern/vfs_subr.c Tue Jan 5 14:21:02 2016 (r293196) > +++ head/sys/kern/vfs_subr.c Tue Jan 5 14:48:40 2016 (r293197) > @@ -1669,7 +1669,8 @@ bnoreuselist(struct bufv *bufv, struct b > > ASSERT_BO_LOCKED(bo); > > - for (lblkno = startn;; lblkno++) { > + for (lblkno = startn;;) { > +again: > bp = BUF_PCTRIE_LOOKUP_GE(&bufv->bv_root, lblkno); > if (bp == NULL || bp->b_lblkno >= endn) > break; > @@ -1677,11 +1678,14 @@ bnoreuselist(struct bufv *bufv, struct b > LK_INTERLOCK, BO_LOCKPTR(bo), "brlsfl", 0, 0); > if (error != 0) { > BO_RLOCK(bo); > - return (error != ENOLCK ? error : EAGAIN); > + if (error == ENOLCK) > + goto again; > + return (error); > } > KASSERT(bp->b_bufobj == bo, > ("bp %p wrong b_bufobj %p should be %p", > bp, bp->b_bufobj, bo)); > + lblkno = bp->b_lblkno + 1; > if ((bp->b_flags & B_MANAGED) == 0) > bremfree(bp); > bp->b_flags |= B_RELBUF; > _______________________________________________ > svn-src-head@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/svn-src-head > To unsubscribe, send any mail to "svn-src-head-unsubscribe@freebsd.org" >
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